While an element of the unexplained variability will likely have arisen though measurement
error, it is more likely that the variation occurred primarily through variation between performances within individuals, as snatch, clean and jerk, and total 1RM
varies by around 2.3 — 2.7 % in elite Olympic weightlifters (McGuigan & Kane, 2004), although test - re-test reliability of the 1RM power clean is nearly perfect in adolescent male athletes, with ICC = 0.98, a
standard error of measurement (SEM) of 2.9 kg and a smallest worthwhile change (SWC) of 8.0 kg (Faigenbaum et al. 2012).